TALLAHASSEE — An investigation of a suspicious-looking letter to the state Department of Highway Safety and Motor Vehicles concluded Monday afternoon that there was "no credible threat," and more than 1,000 state employees were ordered back to their jobs after being evacuated in the morning.

Agency spokeswoman Leslie Palmer said experts from the state Department of Health examined the contents of a threatening letter that mentioned anthrax found in the mailroom.

"There was nothing in the envelope," Palmer said. "It was not considered a credible threat."

The letter was written to Julie Jones, executive director of the Cabinet-level agency. "When they opened it up, it threatened that the letter had white powder in it and said 'This is anthrax and I hope you die,' " Jones said.

The agency's headquarters at 2900 Apalachee Parkway in Tallahassee was evacuated as firefighters surrounded the main parking lot with yellow crime scene tape. Motorists seeking to schedule driving tests or to apply for car registration tags or vehicle titles were turned away for several hours.

Seven employees who work in a second-floor records unit where the letter was discovered were ordered to stay at their desks while hazardous materials experts put them through a decontamination procedure, including taking showers. Firefighters were seen exiting the building and hosing themselves off next to a children's plastic swimming pool.

"We're going to decontaminate those seven employees individually," said Lt. Mike Bellamy of the Tallahassee Fire Department. "Nobody is complaining of any type of ailment. There are no injuries. Individuals are holding up very well."

Anthrax is a potentially fatal disease caused by spore-forming bacterium. It occurs most commonly in wild and domestic animals and can occur in humans exposed to infected animals. Anthrax spores have been used as a bioterrorism weapon.

Workers had no clue what happened. "I have no idea," said Ollie Canty, who works as a tag issuer.

The building is known as the Kirkman Building. It is about 4 miles east of the state Capitol and is the headquarters of employees who process applications for driver's licenses, car and truck registrations and car titles.